What is Alternative Tuning?

Long story short, some guitarists do not use the standard tuning (EBGDAE). It all depends on the musicians' taste and band's genre. So, do not forget to mention the tuning if you submit a tab with nonstandard tuning. State "Drop C" or "Drop D".

Also, almost any tab's tuning may be altered. If you did that, don't forget to mention it. And remember, if you're uncertain of anything simply don't state it. However when you state the tuning it makes your tab more convenient for everyone to use and is cool in general.